Dynamic studies of the initial process of photoreception and transduction in vision are proposed. The research involves kinetic spectroscopy investigations of intermediates of the visual process on timescales of picoseconds to milliseconds. The work is designed to contribute to our understanding of the primary photochemical events in rhodopsin, the visual pigment, and the resulting thermal intermediates in this protein. The link between these early events and the next step in the process of visual triggering is sought. A current hypothesis that photoreception by rhodopsin is linked to activation of the rod outer segment phosphodiesterase is being examined.